1. Field of the Invention
This invention relates to a method of manufacturing a labeled synthetic-resin container having a label fitted on its outer periphery.
2. Description of the Background Art
Hitherto, it has been known to manufacture a container 12 fitted with a label 1a as shown in FIG. 5, in manner as illustrated in FIG. 6.
This known method is such that after a paper-made tubular label 1a placed in a container forming die 2 so as for it to extend closely along the inner periphery thereof as in FIG. 6 (a), a synthetic resin sheet 5 is forced by means of a plug 6a into a space defined by the label 1a as in FIG. 6 (b), whereby pressure forming is effected to form the resin sheet 5 and the label 1a into integral unity. Such method provides an advantage that the label 1a can be formed as such simultaneously with a container in integral relation therewith, label fitting operation being thus simplified.
With the foregoing prior art method, however, it is necessary that in order to allow a paper-made tubular label 1a to be properly fitted on the outer periphery of a formed container, the label 1a, before it is placed in the forming die 2, must be accurately sized and preformed to a desired shape (truncated conical shape in FIG. 7) conforming to the inner surface configuration of the forming die 2 as shown in FIG. 7. Such label preforming operation is very troublesome, which is a cause of poor production efficiency.
Another difficulty with the prior art is that if preforming of the label 1a is inaccurately done so that the label 1a is inconsistent with the inner surface configuration of the forming die 2, the resin sheet 5 is prevented by the label 1a from being formed into a proper container shape, with the result of a forming loss being caused, which poses a fatal problem with the prior art method.